Circuit board and system with a multi-portion socket

ABSTRACT

Circuit board and system with multi-portion sockets, and signal methods practiced thereon are described herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to, but is not limited to, electronicdevices, and in particular, to the field of electronic connections.

2. Description of Related Art

In the current state of integrated circuit technology, electronicdevices such as a central processing unit (CPU), volatile memory, systemon chip (SOC), and the like, are typically assembled into electronicpackages. These electronic packages will commonly have a mating surfacethat is populated with conductive contacts or pads that are electricalcontact points or interfaces for various signal, ground and power paths.The electronic packages and in some cases, the electronic devicesthemselves, are usually directly or indirectly mounted onto anunderlying carrier or circuit board, such as, for example, a printedcircuit board (PCB), a printed circuit card (PCC), a motherboard, andthe like, via a surface mounted socket. The circuit boards, in turn,will electrically couple these mounted electronic packages or electronicdevices to other components via conductive interconnects that aretypically embedded in and/or are on the circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described referencing theaccompanying drawings in which like references denote similar elements,and in which:

FIG. 1 illustrates an exploded view of a circuit board assembly thatincludes a circuit board substrate and a first and a second socketelements, the first socket element being attached to an externalsubstrate in accordance with some embodiments;

FIG. 2 illustrates the assembly of FIG. 1 when the second socket elementhas been coupled to the first socket element to form a complete socketin accordance with some embodiments;

FIG. 3 illustrates the first and second socket elements of FIG. 2, infurther detail, in accordance with some embodiments;

FIG. 4A illustrates a side view of the assembly of FIGS. 1 and 2 afterthe assembly is assembled in accordance with some embodiments;

FIG. 4B illustrates a side view of an electronic component, socket andcircuit board substrate in accordance with some embodiments;

FIG. 4C illustrates a side view of an electronic component, socket andcircuit board substrate in accordance with some embodiments;

FIG. 4D illustrates a side view of an electronic component, socket andcircuit board substrate in accordance with some embodiments;

FIG. 4E illustrates a side view of an electronic component, socket andcircuit board substrate in accordance with some embodiments;

FIGS. 5A to 5D illustrate various views of a circuit board assembly inaccordance with some embodiments;

FIGS. 6A to 6D illustrate various views of a circuit board assembly inaccordance with some embodiments;

FIGS. 7A to 7C are block diagrams of signals being exchanged between twoelectronic components through an external substrate and circuit boardsignal paths in accordance with some embodiments; and

FIG. 8 is a block diagram of an example system, in accordance with someembodiments.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe disclosed embodiments of the present invention. However, it will beapparent to one skilled in the art that these specific details are notrequired in order to practice the disclosed embodiments of the presentinvention. In other instances, well-known electrical structures andcircuits are shown in block diagram form in order not to obscure thedisclosed embodiments of the present invention.

The following description includes terms such as on, onto, over, top,underlying and the like, that are used for descriptive purposes only andare not to be construed as limiting. That is, these terms are terms thatare relative only to a point of reference and are not meant to beinterpreted as limitations but are instead, included in the followingdescription to facilitate understanding of the various aspects of theinvention.

According to various embodiments of the invention, a circuit board isprovided that includes a multi-portioned receiver for receiving anelectronic component, the multi-portioned receiver being coupled to anexternal substrate. For these embodiments, the external substrate mayinclude a dielectric with a lower electrical loss tangent value than adielectric that comprises the circuit board substrate. An electroniccomponent, according to these embodiments, may be, for example, anelectronic package that includes one or more electronic devices, heatdissipation components and one or more substrates. An electroniccomponent may also be an electronic device without a package such as adie or a chip, a chipset, or any other electronic component havingmultiple conductive contacts or pads. An electronic device may be acentral processing unit, system on chip (SOC), graphical co-processor, adigital signal processor, volatile memory, input/output device, chipsetinput/output hub, memory controller or other electronic devices. Invarious embodiments, the receiver, such as a socket, may be mounted onthe circuit board, or may be embedded within the circuit board itself.The receiver may be comprised of at least two detachable portions, atleast one of the portions being coupled to the external substrate.

FIG. 1 depicts an exploded view of a circuit board assembly thatincludes an electronic component and a receiver having two portions orelements, one of which is coupled to an external substrate, inaccordance with various embodiments. For the embodiments, the receiveris a socket 100 that includes two detachable socket portions, a firstsocket element 102 and a second socket element 104. The second socketelement 104 may be electrically coupled to an external substrate 106,while the first socket element 102 may be electrically coupled to acircuit board substrate 112. The socket 100 may receive an electroniccomponent 108 that includes, in this case, a package substrate 109, anelectronic device (not shown) such as a CPU, and a heat spreader 110.

In these embodiments, the first socket element 102 has a U-shape with anadaptedly shaped opening that allows the second socket element 104 to bereceived in the opening. When combined, the two socket elements 102 and104 may form a socket having a substantially rectangular shape. In otherembodiments, however, the first and second socket elements 102 and 104may take on other shapes, thus resulting in a socket that may have adifferent shape other than a substantially rectangular shape.

For the embodiments, the electronic component 108 may be but is notlimited to a land grid array (LGA) package, a micro pin grid array(mPGA) package, a pin grid array (PGA) package, and any other type ofpackages or electronic device that may be mounted onto, for example, asocket. In other embodiments, the electronic component 108 may be a bareelectronic device, without a packaging substrate, that may be directlymounted onto a circuit board such as certain types of CPUs. In variousembodiments, the electronic component 108 may include a flip-chip orother types of chips such as a wire-bonded chip. The package substrate109 may be made of one or more dielectric and/or ceramic layers.Interconnects, such as vias and traces, may be included in the packagesubstrate 109 and may electrically couple the various signal, ground andpower paths of the electronic device in the electronic component 108 tothe socket 100. In some embodiments, the package substrate 109, alongwith its interconnects, may be configured to direct selected signals,such as higher speed signals that are transmitted to and from theelectronic device through a particular portion of the package substrate109, while slower speed signals, ground and power may be directedthrough other portions of the package substrate 109.

In various embodiments, the socket 100 may receive electronic packageshaving multiple conductive contacts. For these embodiments a firstsocket element 102 and a second socket element 104 may combine to formthe complete socket 100 (as depicted in FIG. 2). Each of the first andsecond socket elements 102 and 104 may include mating surfaces 115 thatmay interface with the package substrate 109 when the electroniccomponent 108 is coupled to the first socket element 102 and the secondsocket element 104. For the embodiments, electrical contacts orconnections, such as conductive elements or contacts (see FIG. 4A, ref.406), may be contained in the apertures 114 of the first socket element102 and the second socket element 104. The first socket element 102 mayinclude a receiving feature such as a gap 116 where the second socketelement 104 may be inserted. Note that in these embodiments, the gap 116is depicted as being a complete cut-through that creates a disconnectingvoid in the first socket element 102 thus leaving the surface of theunderlying circuit board substrate 112 exposed. However, in otherembodiments, the gap 116 may not be a complete cut-through and thus willnot result in the socket element 102 having a U-shape. Note further thatin other embodiments, multiple socket elements may be inserted into thegap 116, each of the multiple socket elements may further be coupled todifferent substrates. The first socket element 102 and/or the secondsocket element 104 may be configurably shaped such that the secondsocket element 104 fits into the gap 116 of the first socket element102. For these embodiments, the second socket element 104 may includeears 118 to configurably fit into notches 120 on the side walls of thefirst socket element 102, the notches 120 being part of the receivingfeature (e.g., gap 116) of the first socket element 102.

In various embodiments, the receiving feature (e.g., gap 116) may beused to mate with or receive one or more socket portions (e.g., secondsocket element 104). Although the receiving feature is depicted as beinga gap 116 in FIG. 1, in various other embodiments, the receiving featuremay be an adaptedly shaped portion of the first socket element 102 thatmay receive or mate with additional socket portions. For example, insome embodiments, instead of a complete cut-through gap, the receivingfeature may be a slot formed on the first socket element 102 where thesecond socket element 104 may be inserted. As will be recognized bythose skilled in the art, other variations are also possible.

The circuit board substrate 112 may be electrically coupled to the firstsocket element 102 according to various embodiments. For theembodiments, the circuit board substrate 112 may be comprised ofmultiple interconnects, such as vias and traces, that are embedded inthe circuit board substrate 112. These interconnects may representseparate signal, power and/or ground paths. In various embodiments, thecircuit board substrate 112 may comprise of one or more layers ofdielectrics. The dielectrics that make up the circuit board substrate112 may have specific electrical loss tangent values associated withthem. For example, according to one embodiment, the circuit boardsubstrate 112 may be comprised of Fire Retardant-4 (FR4) dielectrichaving an electrical loss tangent value of about 0.020 to about 0.025.

According to some embodiments, the external substrate 106 may beexternal or physically detached from the circuit board substrate 112. Invarious embodiments, the external substrate 106 may be located adjacentto or on top of the surface of the circuit board substrate 112. Theexternal substrate 106 may be comprised of multiple signal paths. Forthe embodiments, the external substrate 106 may further be comprised ofa dielectric that may minimize signal loss particularly when the signalor signals are being transferred at a high rate. In various embodiments,the electrical loss tangent value of the dielectric comprising theexternal substrate 106 may be a fraction of the electrical loss tangentvalue of the dielectric that comprises the circuit board substrate 112.In some embodiments, the electrical loss tangent for the dielectriccomprising the external substrate 106 is less than or equal to 0.010. Inone embodiment, for example, the electrical loss tangent is from about0.001 to about 0.005. Dielectrics used for the external substrate 106may include but are not limited to a polytetrafluoroethylene (PTFE)dielectric, a polyimide dielectric, a liquid crystal polymer dielectric,and the like.

The external substrate 106, which may be physically disjoined ordetached from the circuit board substrate 112, may be used to carrymultiple signals between the electronic component 108 and, for example,other electronic devices according to some embodiments. For theembodiments, the signals being carried by the external substrate 106 maybe signals of higher speed than signals that may be transmitted throughthe circuit board substrate 112 according to various embodiments. Notethat for these embodiments, the speed of a signal relates to the amountof data being transferred per given time period (e.g., bits or datatransferred per second). In one embodiment, signals that may transferthrough the external substrate 106 is transferred at a rate of 12 GT/s+at a distance of around 6 inches. Of course, these numbers will varydepending upon several factors including for example, the type ofmaterial that comprises the external substrate 106.

In some embodiments, the first socket element 102 may facilitate slowerspeed signals destined for or originating from the electronic component108 while higher speed signals destined for or originating from theelectronic component 108 may be facilitated by the second socket element104. For these embodiments, the references to higher speed signals andslower speed signals are in reference to the signals of different speedsthat may be channeled through the first and second socket elements 102and 104. In various embodiments, ground and power connection for theelectronic component 108 may further be facilitated by the first socketelement 102.

Referring to FIG. 2, which depicts the first socket element 102 and thesecond socket element 104 of FIG. 1 combined or mated to form a completesocket 100 according to various embodiments. For the embodiments, theears 118 (as shown in FIG. 1) of the second socket element 104 has beeninserted into the notches 120 (as shown in FIG. 1) of the first socketelement 102 as indicated by ref. 202. When the electronic component 108is coupled to the socket 100, the second socket element 104 may carry ortransmit signals to and from the electronic component 108. These signalsmay further be carried by the external substrate 106 to and from othercomponents (not shown) that may be directly or indirectly coupled to theexternal substrate 106. As previously discussed, in various embodiments,the signals that are facilitated by second socket element 104 and theexternal substrate 106 may be of higher speed than the signals that arefacilitated by the first socket element 102 and the circuit boardsubstrate 112.

FIG. 3 depicts the first socket element 102 and the second socketelement 104 of FIG. 2, in further detail, according to some embodiments.For the embodiments, an aligning component or components may be includedwith the first socket element 102 and/or the second socket element 104that may align and/or lock into place the second socket element 104. Inthis case, the aligning components are the ears 118 (see FIG. 1) of thesecond socket element 104 and the notches 120 (see FIG. 1) of the firstsocket element 102. The ears 118 may be adapted to slide orfit into thenotches 120 as indicated by ref. 202 in FIGS. 2 and 3. The notches 120and the ears 118 may assure that the first socket element 102 and thesecond socket element 104 are aligned and mated properly. Various otheraligning components, however, may be used in order to assure that thesecond socket element 104 properly mates with the first socket element102 in other embodiments. For example, in one embodiment, the retainingwall 302 of the first socket element 102, which may be used to hold inplace the electronic component 108, may be extended inwards as indicatedby ref. 304. As a result, the retaining wall 302 may also facilitate inholding in place, the second socket element 104. In such an embodiment,the width of the external substrate 106 may be correspondingly reducedto fit between the extended walls 302. In yet another embodiment, thenotches 120 may be on the second socket element 104 instead of the firstsocket element 102 while the ears 118 is located on the first socketelement 102 instead of on the second socket element 104 (see FIG. 1).

FIG. 4A depicts a cross-sectional view of the electronic component 108,socket 100 and circuit board substrate 112 of FIGS. 1 to 3 after beingcombined to form a circuit board assembly according to some embodiments.For the embodiments, the electronic component 108 is on top of thesocket 100, which is further on top of the circuit board substrate 112.The electronic component 108, which comprises of an electronic devicesuch as a CPU or memory device, is electrically coupled to the packagesubstrate 109. The socket 100 having the first socket element 102 thatis electrically coupled to the circuit board substrate 112 via solderballs 402. For the embodiments, the socket 100 further includes thesecond socket element 104, which is electrically coupled to the externalsubstrate 106 via solder balls 404. Each of the first socket element 102and second socket element 104 may include multiple contacts 406 toelectrically couple the package substrate 109 to the circuit boardsubstrate 112 and the external substrate 106. The ends of the contacts406 may protrude out of the top and bottom surfaces of the first socketelement 102 and the second socket element 104 forming contact elementsfor electrically coupling the package substrate 112 to the externalsubstrate 106 and the circuit board substrate 112.

For the embodiments, the second socket element 104 having a smallerheight or thickness than the first socket element 102. As a result ofthis difference in height, a gap 408 is formed between the second socketelement 104 and the circuit board substrate 112. For these embodiments,one end of the external substrate 106 is placed in the gap 408 andelectrically coupled to the second socket element 104 via solder balls404. In various embodiments, the height or thickness of the secondsocket element 104 may be reduced such that the gap 408 may be widenedto allow for, for example, a thicker external substrate 106 to beinserted into the gap 408.

The package substrate 109 may be comprised of multiple interconnects(not shown) such as vias and traces according to some embodiments. Theseinterconnects may be associated with various signal, ground and powerpaths for the electronic device contained in the electronic component108. For the embodiments, the interconnects, which may include tracesand/or vias, may electrically couple the electronic device to thecontacts 406 in the first socket element 102 and the second socketelement 104 through conductive contacts (not shown) on the bottomsurface of the package substrate 109. In some embodiments, selectedsignals such as higher speed signals traveling to and from theelectronic component 108 may be channeled through the portion of thepackage substrate 109 surface that interfaces the second socket element106 as indicated by ref. 409. For these embodiments, slower signals maybe channeled through the package substrate 109 surface that interfacesthe first socket element 102 as indicated by ref. 410. Further, groundand/or power may also be channeled through the package substrate 109surface that interfaces the first socket element 102 (see ref. 410).

For the embodiments, the external substrate 106 is placed adjacent to oron the surface of the circuit board substrate 112 and may be a flexiblecircuit. In one embodiment, the external substrate 106 is a flex circuitsuch as a polyimide-based flex circuit. In other embodiments, however,the external substrate 106 may be a non-flex circuit. An externalsubstrate 106 that is a flexible circuit may provide certain beneficialcharacteristics in some embodiments. For example, in one embodiment, aflexible circuit may allow for additional space on the surface of thecircuit board substrate 112 for mounting additional components onto thecircuit board substrate 112. That is, by using a flexible circuit as theexternal substrate 106, additional components may be mounted on thesurface of the circuit board substrate 112 underneath the externalsubstrate 106 as indicated by ref. 412. In addition, a flexible circuitmay provide more tolerance for coupling the flexible circuit (i.e.,external substrate 106) to other components. By providing extratolerance, coupling of the external substrate 106 to other componentsmay be facilitated by providing additional “slack” to properly couplewith other components.

Although the first socket element 102 and the second socket element 104depicted in FIG. 4A are coupled to the circuit board substrate 112 andthe external substrate 106 via solder balls 402 and 404, in otherembodiments other electrical connectors may be used. For instance, pins,clips, conductive elastomers and other coupling devices may also beemployed. For example, in one embodiment, the first socket element 102and/or the second socket element 104 may be electrically coupled to thecircuit board substrate 112 and/or the external substrate 106 usingpressure type connection components (e.g., conductive elastomers) suchas those that may be used in land grid array connections.

Referring to FIG. 4B depicting a cross-sectional view of an electroniccomponent 108, socket 100 and circuit board substrate 112 according tosome embodiments. For these embodiments, the receiving feature (e.g.,gap 116 in FIG. 1) of the first socket element 102 is not a completecut-through. Instead, the first socket element 102 has a gap bridgingportion 414 that bridges the receiving feature (e.g., gap 116). As aresult, in these embodiments, the first socket element 102 will not havea true U-shape but instead will have a generally rectangular or O-shape.Further, in these embodiments, the external substrate 106 may rest ontop of the gap bridging portion 414 instead of on the surface of thecircuit board substrate 112 as in the embodiment depicted in FIG. 4A. Inorder to accommodate the gap bridge portion 414 note that the secondsocket element 104 has a significantly smaller profile (e.g., height)than the first socket element 102.

FIG. 4C depicts a cross-sectional view of an electronic component 108,socket 100 and circuit board substrate 112 according to someembodiments. For these embodiments, the receiving feature (e.g., gap 116in FIG. 1) of the first socket element 102 is again not a completecut-through. Instead, as in the previous embodiments, the first socketelement 102 has a gap bridging portion 414 that bridges the receivingfeature (e.g., gap 116). In addition, a compliant pressure component, inthis case, a pressure pad 416 lies on top of the gap bridging portion414 between the gap bridging portion 414 and the external substrate 106.Such a pressure component (e.g., pressure pad 416), which may becomprised of a elastomeric material, may assure that good electricalcontact is maintained between, for example, the second socket element104 and the package substrate 109.

FIG. 4D depicts a cross-sectional view of an electronic component 108,socket 100 and circuit board substrate 112 according to someembodiments. For these embodiments, the receiving feature (e.g., gap 116in FIG. 1) of the first socket element 102 is again not a completecut-through. Again, in these embodiments, the first socket element 102has a gap bridging portion 414 that bridges the receiving feature (e.g.,gap 116). In addition, a compliant pressure component, in this case,springs 420 that have cantilever shapes lie on top of the gap bridgingportion 414 between the gap bridging portion 414 and the externalsubstrate 106. Such a pressure component (e.g., springs 420) may assurethat good electrical contact is maintained between, for example, thesecond socket element 104 and the package substrate 109.

FIG. 4E depicts a cross-sectional view of an electronic component 108,socket 100 and circuit board substrate 112 according to someembodiments. For these embodiments, the receiving feature (e.g., gap 116in FIG. 1) of the first socket element 102 is again not a completecut-through. Again, in these embodiments, the first socket element 102has a gap bridging portion 414 that bridges the receiving feature (e.g.,gap 116). However, in these embodiments, the receiving feature receivesa thick external substrate 420 that may or may not be semi or completelyrigid. Note that as with the above embodiments, the profile (e.g.,height) of the second socket element 104 is smaller than the firstsocket element 102 thus facilitating the insertion of such a thickexternal substrate 420.

FIGS. 5A to 5C depicts exploded and intact views of a circuit boardassembly with two electronic components, in this case, two electronicpackages, coupled together by two surface mounted receivers and aexternal substrate according to some embodiments. For these embodiments,two electronic packages, a first electronic package 502 and a secondelectronic package 504, are mounted on top of first socket elements 506and 508 and second socket elements 510 and 512. The first socketelements 506 and 508 are on a circuit board substrate 514. The secondsocket elements 510 and 512 are coupled together by an externalsubstrate 516. For the embodiments, the second socket elements 510 and512 may be inserted into gaps 518 of the first socket elements 506 and508 to form complete sockets 520 and 522 as depicted in FIG. 5B.

In various embodiments, the external substrate 516 may be a flexiblecircuit that may facilitate the coupling of the external substrate 516to the second socket elements 510 and 512. In some embodiments,additional components may be mounted onto the surface of the circuitboard substrate 514 underneath the external substrate 516 (as indicatedby ref. 524 in FIGS. 5B and 5C).

In some embodiments, the external substrate 516 may transfer higherspeed signals between the two electronic packages 502 and 504 throughmultiple signal paths that may be present in the external substrate 516.For these embodiments, slower signals, ground and/or power may transferbetween the electronic packages 502 and 504 and/or other componentsthrough the first socket elements 506 and 508 and through the circuitboard substrate 514.

FIG. 5D depicts a partial split side view of the circuit board assemblyof FIGS. 5A to 5C in accordance with various embodiments. For theembodiments, the two electronic packages 502 and 504 are electricallycoupled by the external substrate 516 and circuit board signal paths 524that are integral of or embedded within the circuit board substrate 514.As previously described, in various embodiments, higher speed signal maytransfer between the two electronic packages 502 and 504 throughexternal substrate 516 while slower speed signals may transfer betweenthe two electronic packages 502 and 504 via circuit board signal paths524 which, in this case, are conductive interconnects (such as vias andtraces). Although not depicted, the circuit board signal paths 524 mayfurther be coupled with other components and may facilitate ground andpower for the electronic packages 502 and 506. Note that although inFIG. 5D (as well as in FIG. 6D) the circuit board signal paths 524 aredepicted as being underneath the surface of the circuit board substrate514, in other embodiments, one or more of the circuit board signal paths524 may actually be located on the surface of the circuit boardsubstrate 514.

In various embodiments, the circuit board signal paths 524 may include aplurality of traces and vias that form multiple signal paths between thetwo electronic packages 502 and 504. The circuit board signal paths 524may also include one or more paths for ground and power, which may bedirected away from the two electronic packages 502 and 504.

FIGS. 6A to 6C depicts various exploded and intact views of a circuitboard assembly with a first electronic component, an electronic package,coupled to second electronic component, a chipset, by an externalsubstrate, according to some embodiments. For the embodiments, anelectronic package 602 is mounted onto a first socket element 604 and asecond socket element 606. The first socket element 604 and secondsocket element 606 are located on a circuit board substrate 608. Thefirst socket element 604 and the second socket element 606 combining toform a surface mounted receiver or, in this case, a socket 609 (seeFIGS. 6B and 6C). The second socket element 606 is coupled to anexternal substrate 610 at one end of the external substrate 610. At theother end of the external substrate 610, the external substrate 610 maybe coupled to a connector 612. In various embodiments, the externalsubstrate 610 may include a plurality of signal paths. The connector612, in turn, may be coupled to a circuit board connector 614 that iscoupled to the surface 618 of the circuit board 608 (see FIGS. 6B and6C). The circuit board connector 614 may be electrically coupled to achipset 616 through interconnects that run underneath and/or on thesurface 618 of the circuit board substrate 608.

For these embodiments, it may be beneficial to locate the circuit boardconnector 614 close to the electronic package (e.g., chipset 616). Thatis, in some embodiments, the circuit board substrate 608 may becomprised of a dielectric that has a relatively high electrical losstangent value such as an FR4 dielectric. Therefore, significant signalloss may occur as a signal is traveling between the circuit boardconnector 614 and chipset 616 if the distance between the two is large.The amount of loss, of course, will depend on several factors including,for example, the frequencies of the signals being transmitted and theactual distance being traveled through the circuit board substrate 608by the signal. By locating the circuit board connector 614 close to thedirectly soldered or bonded electronic package (e.g., chipset 616),signal loss that may occur between the circuit board connector 614 andfor example, the chipset 616, may be reduced.

FIG. 6D depicts a partial split side view of the circuit board assemblyof FIGS. 6A to 6C in accordance with various embodiments. For theembodiments, the electronic package 602 and the chipset 616 are directlycoupled via first circuit board signal paths 620 that is integral of orembedded within the circuit board substrate 608. The electronic package602 and the chipset 616 are further coupled by the external substrate610 external to the circuit board substrate 620 along with secondcircuit board signal paths 622. In various embodiments, higher speedsignal may transfer between the electronic package 602 and the chipset616 through external substrate 610 and the second circuit board signalpaths 622 while slower speed signals may transfer between the electronicpackage 602 and the chipset 616 via the first circuit board signal paths620.

In various embodiments, the first circuit board signal paths 620 mayinclude a plurality of traces and vias that form multiple signal pathsbetween the electronic package 602 and the chipset 616. The firstcircuit board signal paths 620 may also include one or more paths forground and power, which may be directed away from the electronic package602 and the chipset 616. Although not shown, the first circuit boardsignal paths 620 may further be coupled with other circuit boardcomponents.

Unlike the embodiment depicted in FIGS. 5A to 5D, the signals beingtransmitted through the external substrate 610 for this embodiment arenot carried entirely through the external substrate 610. Instead, thesignals being transmitted through the external substrate 610 must travelthrough the second circuit board signal paths 622 between the circuitboard connector 614 and the chipset 616.

In addition to the embodiments described above, other configurations arepossible in other embodiments. For example, in other embodiments, twoelectronic packages that are both bonded or soldered directly on to acircuit board substrate may also be coupled via an external substrateusing, for example, two circuit board connectors. Further, in someembodiments, more than two electronic packages may be linked together ona circuit board substrate via multiple external substrates.

Other embodiments includes, for example, a socket that includes morethan two socket elements such as a socket having three, four, five ormore socket elements, where three or more of the socket elements may becoupled to three or more substrates. In such embodiments, the three ormore substrates may be coupled to two or more electronic components thuslinking the socket to multiple electronic components through three ormore substrates.

Referring to FIGS. 7A to 7C depicting signals being exchanged betweentwo electronic components 702 and 704 through two sets of signal paths,a plurality of external substrate signal paths and a plurality ofcircuit board signal paths according to various embodiments. For theembodiments, the external substrate signal paths and the circuit boardsignal paths being physically disjoined or separated from each other. Inthese embodiments, the external substrate signal paths and the circuitboard signal paths may be bi-directional and/or unidirectional. Invarious embodiments, a plurality of signals having different speeds maybe carried by each set of signal paths.

FIG. 7A depicts a first electronic component 702 transmitting signals toa second electronic package 704 via external substrate signal paths andcircuit board signal paths as depicted in accordance with oneembodiment. For this embodiment, the second electronic component 704 maybe a slave or servant component to the first electronic component 702only receiving signals from the first electronic component 702 and nottransmitting signals to the first electronic component 702. As a result,for this embodiment, signals are only transmitted in one direction. Invarious embodiments, the transmitted signals carried through theexternal substrate signal paths may be signals of higher speed than thesignals carried by the circuit board substrate paths. In someembodiments, signals of different speeds may even propagate within thesame set of signal paths (e.g., external substrate signal paths orcircuit board signal paths). Thus, for example, the external substratesignal paths may, by themselves, carry signals of different speeds.

According to another embodiment, the first electronic component 702 maytransmit signals to the second electronic component 704 through only theexternal substrate signal paths and not through the circuit board signalpaths as depicted in FIG. 7B. For this embodiment, the first electroniccomponent 702 may, however, receive signals from the second electroniccomponent 704 via the circuit board signal paths. In this embodiment,the external substrate signal paths and the circuit board signal pathsare not bi-directional. That is, note that in this embodiment, allsignals traveling through a particular set of signal path (i.e., theexternal substrate signal paths or the circuit board signal paths) aretraveling in one direction only. Again, as in the embodiment depicted inFIG. 7A, signals being carried by the external substrate signal pathsmay be higher speed signals than the signals carried by the circuitboard signal paths. Also again, each set of signal paths (e.g., externalsubstrate signal paths or circuit board signal paths) may carry signalsof different speeds.

According to another embodiment, each set of signal paths (externalsubstrate signal paths and the circuit board signal paths) may allowbi-directional signal transmissions as depicted in FIG. 7C. For thisembodiment, the first electronic component 702 may transmit or receivesignals from the second electronic component 704 through both theexternal substrate signal paths and the circuit board signal paths.Again, as in the embodiments depicted in FIGS. 7A and 7B, signals beingcarried by the external substrate signal paths may be higher speedsignals than the signals carried by the circuit board signal paths. Alsoagain, each set of signal paths (e.g., external substrate signal pathsor circuit board signal paths) may carry signals of different speeds.

In some embodiments, the signals being transmitted and received by anelectronic component may use the same and/or different signal paths(i.e., external substrate signal paths and/or circuit board signalpaths) for transmitting and receiving signals. For example, in someembodiments, the first electronic component 702 may use the sameexternal substrate signal paths for transmitting and receiving signalsto and from the second electronic component 704. Such signal paths mayrepresent true bi-directional signal paths. Similarly, the firstelectronic component 702 may use the same circuit board signal paths forboth receiving and transmitting signals to and from the secondelectronic component 704. In other embodiments, however, the firstelectronic component 702, may use, for example, only specific externalsubstrate paths for receiving signals from the second electroniccomponent 704, while other external substrate paths may be used only fortransmitting signals to the second electronic component 704. Similarly,for such embodiments, some of the circuit board substrate paths may bededicated for transmitting signals from the first electronic component702 to the second electronic component 704 while other circuit boardsubstrate paths may be dedicated for receiving signals by the firstelectronic component 702 from the second electronic component 704. Inyet other embodiments, the signals paths used by, for example, the firstelectronic component 702 may include a combination of bothbi-directional signal paths as well as one or unidirectional signalpaths (external substrate signal paths and/or circuit board signalpaths).

In the following, examples of different signaling schemes between thefirst and the second electronic components 702 and 704 via the circuitboard signal paths and/or the external substrate signal paths areprovided according to various embodiments.

In the first example, the first electronic component 702 transmits aplurality of first signals at a first signal speed through the circuitboard signal paths to the second electronic component 704. The firstelectronic component 702 further transmits a plurality of second signalsat a second signal speed through the external substrate signal paths tothe second electronic component 704. In various embodiments, the secondsignal speed may be higher than the first signal speed. In someembodiments, the second electronic component 704 may transmit and thefirst electronic component 702 may receive, a plurality of third signalsat a third signal speed via either the circuit board signal paths or theexternal substrate signal paths. If the plurality of third signals arereceived through the circuit board signal paths, then the third signalspeed of the plurality of third signals may be lower than the secondsignal speed of the plurality of second signals and may be equal to thefirst signal speed of the plurality of first signals. In someembodiments, at least some of the first and third signals may betransmitted and received through the same signal paths (e.g.,bi-directional circuit board signal paths). If, on the other had, theplurality of third signals are received by the first electroniccomponent 702 through the external substrate signal paths, then thethird signal speeds of the plurality of third signals may be higher thanthe first signal speed of the plurality of first signals and may beequal to the second signal speed of the plurality of second signals. Insome embodiments, at least some of the second and third signals may betransmitted and received thorough the same signal paths (e.g.,bi-directional external substrate signal paths).

In a second example, the second electronic component 704 may transmitand the first electronic component 702 may receive, a plurality of firstsignals at a first signal speed via the circuit board signal paths. Thesecond electronic component 704 may further transmit and the firstelectronic component 702 may further receive, a plurality of secondsignals at a second signal speed via the external substrate signalpaths. In some embodiments, the first electronic component 702 maytransmit and the second electronic component 704 may receive, aplurality of third signals at a third signal speed via either thecircuit board signal paths or the external substrate signal paths. Insome embodiments, the second signal speed of the plurality of secondsignals may be higher than the first signal speed of the plurality offirst signals.

In a third example, the first electronic component 702 may transmit andthe second electronic component 704 may receive, a plurality of firstsignals at a first signal speed via the circuit board signal paths. Inthis example, the second electronic component 704 may transmit and thefirst electronic component 702 may receive, a plurality of secondsignals at a second signal speed via the external substrate signalpaths. In some embodiments, the second signal speed of the plurality ofsecond signals may be higher than the first signal speed of theplurality of first signals.

Referring now to FIG. 8, where a system 800 in accordance with someembodiments is shown. The system 800 includes a microprocessor 802 thatmay be coupled to a bus 804. The system 800 may further includetemporary memory 806, a network interface 808, an optional non-volatilememory 810 and an input/output (I/O) device interface unit 812. In someembodiments, the input/output device interface unit 812 may be akeyboard, a cursor control device and/or other I/O device. One or moreof the above enumerated elements, such as microprocessor 802, temporarymemory 806, non-volatile memory 810, and so forth, may be coupled to thenovel circuit board apparatuses described above.

Depending on the applications, the system 800 may include othercomponents, including but not limited to chipsets, RF transceivers, massstorage (such as hard disk, compact disk (CD), digital versatile disk(DVD), graphical or mathematic co-processors, and so forth.

One or more of the system components may be located on a single chipsuch as a system on chip (SOC). In various embodiments, the system 800may be a personal digital assistant (PDA), a wireless mobile phone, atablet computing device, a laptop computing device, a desktop computingdevice, a set-top box, an entertainment control unit, a digital camera,a digital video recorder, a media recorder, a media player, a CD player,a DVD player, a network server, or device of the like.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. This application isintended to cover any adaptations or variations of the embodiments ofthe present invention. Therefore, it is manifestly intended that thisinvention be limited only by the claims.

1. A circuit board apparatus, comprising: a first substrate; and a firstportion of a first socket having a first plurality of contacts coupledto the first substrate, and adapted to cooperate with at least a secondplurality of contacts of a second portion of the first socket to bemated with the first portion, to provide electrical contacts for a firstelectronic component to be mated with the first socket, the firstportion further having at least a first receiving feature to facilitatethe mating of the second portion to the first portion.
 2. The circuitboard apparatus of claim 1, wherein said first portion of the firstsocket is to facilitate at least ground and power to the firstelectronic component through the substrate.
 3. The circuit boardapparatus of claim 1, wherein the second plurality of contacts areadapted to be coupled to a second substrate, and the first and secondplurality of contacts are adapted to facilitate routing of signalsoriginated from or destined for the first electronic component throughat least two plurality of paths, a first plurality of paths through thefirst substrate, and a second plurality of paths through the secondsubstrate.
 4. The circuit board apparatus of claim 1, wherein thecircuit board apparatus further comprises a third portion of a secondsocket having a third plurality of contacts coupled to the firstsubstrate, and adapted to cooperate with at least a fourth plurality ofcontacts of a fourth portion of the second socket to be mated with thethird portion, to provide electrical contacts for a second electroniccomponent to be mated with the second socket, the third portion furtherhaving at least a second receiving feature to facilitate the mating ofthe fourth portion to the third portion.
 5. The circuit board apparatusof claim 4, wherein the second and fourth plurality of contacts arecoupled to each other through a second substrate, and the first, second,third and fourth plurality of contacts are adapted to facilitate routingof first and second plurality signals to be exchanged between the firstand the second electronic components, through at least two plurality ofpaths, a first plurality of paths through said first substrate, and asecond plurality of paths through the second substrate.
 6. The circuitboard apparatus of claim 5, wherein the signals are routed through thefirst and second plurality of paths at a first and a second speedrespectively, with the second speed higher than the first speed.
 7. Amethod, comprising: transmitting at a first speed, first signals from afirst electronic component to a second electronic component through afirst plurality of signal paths disposed in a first substrate; andtransmitting at a second speed, second signals from the first electroniccomponent to the second electronic component through a second pluralityof signal paths disposed in a second substrate, the first and the secondsubstrates being physically disjoined from each other.
 8. The method ofclaim 7, wherein said second speed is higher than the first speed
 9. Themethod of claim 7, wherein the method further comprises receiving at thefirst electronic component and at a third speed, third signalstransmitted from the second electronic component through a thirdplurality of signal paths disposed in a selected one of the first andsecond substrate.
 10. The method of claim 9, wherein the third pluralityof signal paths are disposed in the first substrate, and the secondspeed is higher than the third speed.
 11. The method of claim 10,wherein the first and third speeds are the same speed.
 12. The method ofclaim 10, wherein at least some of the first and third signal paths arethe same signal paths.
 13. The method of claim 9, wherein the thirdplurality of signal paths are disposed on the second substrate, and thethird speed is higher than the first speed.
 14. The method of claim 13,wherein the second and third speeds are the same speed
 15. The method ofclaim 13, wherein at least some of the second and third signal paths arethe same signal paths.
 16. The method of claim 9, wherein the methodfurther comprises the second electronic component transmitting the thirdsignals at the third speed through the selected one of the first and thesecond substrate.
 17. The method of claim 7, wherein the method furthercomprises the second electronic component receiving the first and thesecond signals at the first and the second speed respectively.
 18. Amethod, comprising: receiving at a first electronic component and at afirst speed, first signals sent from a second electronic componentthrough a first plurality of signal paths disposed in a first substrate;and receiving at a second electronic component and at a second speed,second signals sent from the first electronic component through a secondplurality of signal paths disposed in a second substrate, the first andthe second substrates being physically disjoined from each other. 19.The method of claim 18, wherein the method further comprisestransmitting at a third speed, third signals from the first electroniccomponent to the second electronic component through a third pluralityof signal paths disposed in a selected one of the first and the secondsubstrate.
 20. The method of claim 19, wherein the method furthercomprises the second electronic component receiving the third signals atthe third speed through a substrate selected from the group consistingof the first substrate and the second substrate.
 21. The method of claim18, wherein the method further comprises the second electronic componenttransmitting at the first and the second speed, the first and thesignals respectively.
 22. A method, comprising: transmitting at a firstspeed, first signals from a first electronic component to a secondelectronic component through a first plurality of signal paths disposedin a first substrate; and receiving at the first electronic componentand at a second speed, second signals sent from a second electroniccomponent through a second plurality of signal paths disposed in asecond substrate, the first and the second substrates being physicallydisjoined from each other.
 23. The method of claim 22, wherein themethod further comprises the second electronic component receiving thefirst signals at the first speed, and transmitting the second signals atthe second speed.
 24. A system comprising: a first substrate having afirst plurality of signal paths; a first portion of a first sockethaving a first plurality of contacts coupled to the first plurality ofsignal paths; a second portion of the first socket mated with the firstportion, the second portion having a second plurality of contacts; athird portion of a second socket having a third plurality of contactscoupled to the first plurality of signal paths; a fourth portion of thesecond socket mated with the third portion, the fourth portion having afourth plurality of contacts; a second substrate having a secondplurality of signal paths coupling the second plurality of contacts tothe fourth plurality of contacts; and an input/output device interfaceunit coupled to the first plurality of signal paths.
 25. The system ofclaim 24, wherein the system further comprises a first and a secondelectronic component mated with the first and the second socketsrespectively.
 26. The system of claim 25, wherein the first electroniccomponent comprises a processor.
 27. The system of claim 26, wherein thesecond electronic component comprises a selected one of a graphicsco-processor and a digital signal processor.
 28. The system of claim 24,wherein the input/output device interface unit is adapted to interfaceat least a selected one of a keyboard and a cursor control device. 29.The system of claim 24, wherein the system further comprises a massstorage device coupled to the first plurality of signal paths.
 30. Thesystem of claim 24, wherein the system is a selected one of a set-topbox, a media recorder, and a media player.